Oakland Police Department's internal communications about the Occupy Oakland movement — which the Guardian obtained through the California Public Records Act — confirm what many protesters already know: plainclothes officers frequent meetings, police monitor Occupy Oakland's online communications, anarchists are feared, and police use of force that injures protesters, often brutally, is common practice.

The documents include meeting notes and activity logs from Oct. 25, when officers from Oakland and nearby cities infamously tried to dismantle the tents in front of City Hall. In a confrontation lasting more than 24 hours, officers deployed tear gas, rubber bullets, flash bang grenades and pepper bombs, injuring dozens, including Scott Olsen, a 24-year-old veteran who had served two tours in Iraq.

Logs from Nov. 2-3 — during Oakland's general strike, first port shutdown, and occupation of the Travelers Aid Society building — also detail the use of tear gas and other "less than lethal" weaponry and injuries. In total, the reports on arrests and use of force, as well as complaints filed with the OPD, spanning from Oct. 25, 2011 to Feb. 11, 2012, paint the picture of an agency engaged in something akin to urban warfare against a feared enemy.

"Surveillance teams will consist of undercover officers supervised by a sergeant. They will operate from elevated positions or walk within the crowd and report threat information to the MFF commander via the surveillance team leader," read an Oct. 24 operations memo. Throughout the day on Oct. 25, officers make note of constantly checking Occupy Oakland's website, Facebook, Twitter, and Livestream to anticipate protesters actions.

On Nov. 3, officers discuss changing the radio frequency that they were using for communication after protesters discovered it and began livestreaming the channel.

Officers also seem wary of the power of social networking to influence their strategies. Deputy Chief Eric Breshears suggests that the "port is isolated" so police should simply "surround [protesters] and start negotiating." But the strategy is rejected with this response: "None are truly isolated. Twitter."

OPD has come under fire in the past for the actions of undercover cops. In 2006, documents released to the ACLU revealed that undercover officers had spied on an and potentially infultrated an anti-war march during a Port blockade protest (police claimed that they had led the protest march, but activists maintain that the march was certainly not led by uncdercover police.) At that protest, police ended up blasting the crowd with tear gas and rubber bullets, as well as attacking with wooden pallets and motorcycles; 50 were injured.

Officers sometimes make judgments based on class or political beliefs. In an Oct. 24 briefing, a plainclothes officer, having strolled through the encampment, reports that "the group is diverse, made up of persons including self-proclaimed anarchists, labor unions, long term homeless individuals, special cause supporters and others."

Oakland police also noted the presence of Occupy SF protesters and groups including California Nurses United.

"We just got info that the San Francisco group is coming here in support of the Oakland folks," Deputy Chief Jeff Israel reported on Oct. 25. On Nov. 3, he recorded protesters "at Wells Fargo in SF now, 150-300 people. Recruiting Occupy Oakland and Occupy SF." At another meeting three hours later, Israel reports to a meeting that "Occupy SF is sending support. Might be here already."

But Oakland cops were less impressed by their San Francisco counterparts. OPD Chief Howard Johnson reportedly said: "SFPD is mad. They wanted to come play with us. Had 19 people. Had them protect our PAB [Police Administration Building]. Problem is, they don't have gas masks. Couldn't get close to the action."